Gas Cap for '70 Nova

[m22mike]

Don't drill your vented caps... ...I am quit sure they are designed to allow some positive pressure in the tank, it helps the crappy little fuel pump work better.
When I have been driving Black Beauty... ...and pull in for gaz, I always crack the cap for a few seconds to allow the tank to vent off. Never tried it after the car has set all night.
If you and try blowing through the hole on the back of a vented cap you will notice it requires a small amout of effort before you get any flow.
The vented cap also has a negative pressure relief built into it as well. You can check this function by sucking on that little round thing in the back of the cap..
For you guys that are not in touch with your masculine side or are
affraid of germs, use a Mighty Vac...

[Salvatore]

WOW Mike, learn something new about you every day! Is this how it is done?

[JRSully]

I have a Spectra 70 model tank in my 70 Nova, and only the EEC cap (the wide one) fits, a standard cap will not fit, pain in ass. Somebody mentioned a fix for this,? I'm all ears and eyes, let me know

[67BelAir427]

Jim,
You must have had the exact same experience I had. We are not talking about a little pressure in the tank.That "vented" cap seals the tank tight. When I remove the cap you can see the entire tank "flex" as the vapor escapes. For sure you would blow that back through the carbs on a hot day and you'd be stuck. I too would like to hear from someone who has bought these parts and found a solution to the problem. Marc